[macosx] Unable to write in to the text box field [MAC OS X 10.8.3] [Regression]

Java version: jre-7u17-macosx-x64

Last version it worked in: 7u6
 
OS: Mac OS X 10.8.3

Browser: Safari 6.0.3

Hardware: 2.9 GHz Intel Core i7

Applet link:http://www.multichat.no/vakt/

User Agent String: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/536.28.10 (KHTML, like Gecko) Version/6.0.3 Safari/536.28.10

Bug description: Since the security issues arose and changes to Java have been made, I cannot post comments in a Norwegian chat site where I am a moderator. Java allows me to come into the site and choose a room to enter. I can go into the room, can operate as a moderator, however, I can not send any text to the room. In essence then, I can only participate as a silent moderator as I can not comment, ask or respond to questions.

Steps to reproduce:
1. Go to site http://www.multichat.no/vakt/
2. Enter password
3. Choose room
4. Enter room with nickname
5. Greet participants and send text to the room via the return key. (this is where the process breaks down as the text does not leave my mac.

Reproduced by Java.com team: No

Screen shot: http://imgur.com/mOSTYZH and http://i.imgur.com/mOSTYZH.png